Since entrance of the touch era marked by Apple products, the capacitive touch screen has become the first choice for mobile phones, tablet personal computers and touch laptops by virtue of its stable performance and good touch. No matter what touch technology is, the cover is always a necessary protective part. While the glass cover has been the mainstream of cover with the aid of high permeability and strong scratch resistance.
In the current market, the Moh's hardness value of high-alumina silicate cover glass is generally 6. Moreover, glass elements under this resistance are assembled to mobile phones, tablet personal computers and touch laptops. However, when gravel or dust containing silicon dioxide (SiO2, with Moh's hardness of 7H) rubs cover glass of the smart phone, it is easy to result in scratches and minor damages, which not only shortens the service life of equipment, but also increases maintenance cost.
For the purpose of improving the hardness of glass cover, some merchants have begun to pay attention to sapphire glass with Moh's hardness of 9H. If the Moh's hardness of cover material is greater than 7H, wear caused by gravels can be resisted. The impact resistance of sapphire is stronger than that of glass, but compared to high-alumina silicate glass, the price of sapphire glass is exceeded by about 10 times, and energy consumed by the sapphire glass by about 100 times. For the visible light transmittance through 1 mm of the sapphire is 80%, the transmittance is rather low. This results in shortening the life of battery and being easy to break.
Glass ceramic is a multi-phase solid material containing a large number of microcrystals obtained by controlling glass crystallization during glass heat treatment. Furthermore, it also has the advantages of high transparency of glass and good mechanical property of ceramic. Hence, an effective way to improve glass hardness is provided.